If you have that many fuses available (you should never need that many in a TD) put each light on its own fuse. You'll never have to worry about amp rating and if something happens to one light, the rest will still work. Thats how I would do it, IMHO. Jim

Its always good to have some of your lighting circuits on a seperate fuse, if you are away and a wire shorts behind a panel at least the lights on the other fused circuit will work, if they are all on one you have no lights.......

My interior lights, fan, fantastic vent fan, reading lights, all run off heavy speaker wire and 1, 15a fuse.... the wire is that clear sheathed stuff with one copper colored lead and one silver lead, from home depot, bought by the foot.

Most of that stuff draws 2-4 amp at the most...... 40 watts draws a bit over 3 amps and the wire I used is easily good for 15 amps...

If you want to get a clue, take a look at the wire size inside the fuse... then look at your wire.... my wire diameter is approximately 3 times the size of the fuse..... no doubt the fuse will go before any damage occurs.

No doubt you are right the fuse will go in time and all your systems would be down. If for some reason you cannot repair the cause of the fuse blowing (say it's hidden behind a panel) then until you get back to your shop everythings down and your weekend is ruined.

Fuse thickness and copper wire thickness will generally not bear any relation to each other, they are of differing materials. Fuse wire and other fuseable material is used for a specified purpose.

You are right. Fuse wire can generally be of the same thickness as the power wire and will blow first.... I err on the side of safety, and to keep line loss at a minimum...... I have a 30 amp fuse at the battery with a 12 inch run to a fuse block, and my reading lights run off one 15 amp fuse, the fan, fanstastic fan and dome light off another 15 amp.... So, I could lose reading lights, or the rest, but none are weekend killers..... and the wiring is pretty simple, and most is buried in the walls.... if it works now, I expect it will be working in 10 years. The main connections are all easily accessed if I wanted to bother, behind lights or bezels.

The one thing I have to do, still, is get a 15 amp, 115v breaker, to put in the shore power line.... that wire feeds 3 power strips, one for general activities, one for a/c, tv, heater, and one for microwave and galley. All those are surge protectors with built-in circuit breakers, but I have no protection between shore power coming in at the wall, and the power strips.. will fix that this week.....

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I will off this general tip: where I run wire under the tear, through holes in the frame, I put a glob of silicone at each contact point to keep the wire from chafing.... All of it is sheathed, but this is an extra protection type thing......